Communication Standards and Technologies Flashcards
(154 cards)
1
Q
How do IoT networks’ capabilities compare to IT networks?
A
IoT networks typically have more limited capabilities compared to IT networks.
2
Q
What are the characteristics of most wireless IoT networks that affect data exchange?
A
Most wireless IoT networks are lossy and constrained, which significantly restricts the speed of data exchange.
3
Q
What challenge is posed by the large number of IoT nodes and sensors?
A
The massive number of IoT nodes and sensors requires special provisioning and configuration, which may increase the cost of connectivity.
4
Q
How should IoT networks be designed in relation to connectivity fees?
A
IoT networks should be designed to minimize connectivity fees.
5
Q
In remote areas like mining or forestry where should the IOT sensors be deployed?
A
In remote areas, IoT sensors should be deployed in areas with limited access to electricity and regular cellular communication.
6
Q
What type of communication technologies are required for IoT sensors in rural and remote areas?
A
Low-power communication technologies that can cover wide areas are required for IoT sensors in rural and remote areas.
7
Q
Why do inexpensive and tiny IoT sensors face restrictions in their communication capabilities?
A
Inexpensive and tiny IoT sensors have limited processing and power capabilities, restricting their ability to use any communication technology or protocol.
8
Q
What have been developed to address the communication needs of IoT devices?
A
Various communication standards, technologies, and protocols have been developed to address IoT needs.
9
Q
What are lightweight IoT technologies designed for?
A
Lightweight IoT technologies are designed for massive IoT use cases where reducing hardware and connectivity costs is crucial.
10
Q
In what IoT scenarios are mission-critical technologies required?
A
Mission-critical IoT technologies are required in use cases like drone control or automatic guided vehicles (AGVs), where the reliability and availability of the network are imperative.
11
Q
Why is it important for IoT network architects to understand different IoT technologies and protocols?
A
IoT network architects need to understand the advantages and disadvantages of different technologies, standards, and protocols to choose the right technology for each use case.
12
Q
How do communication technologies for massive IoT differ from those for mission-critical IoT?
A
Technologies for massive IoT focus on reducing hardware and connectivity costs, while mission-critical IoT technologies emphasize reliability and network availability.
13
Q
What must an IoT network architect consider when designing an IoT network?
A
An IoT network architect must consider the security policies and design practices based on the specific requirements of the IoT use case and application.
14
Q
What are the consequences of not carefully designing an IoT network?
A
Failure to carefully design the network may lead to difficulties in managing, troubleshooting, scaling, and adapting the network.
15
Q
What determines how elements of an IoT network communicate with each other?
A
The network topology determines how elements of an IoT network communicate with each other.
16
Q
What factors influence the choice of network topology for an IoT use case?
A
The choice of network topology is influenced by the implementation cost, complexity, power consumption, and reliability, as dictated by the IoT use case.
17
Q
When is a peer-to-peer IoT network established?
A
A peer-to-peer IoT network is established when both nodes are capable of implementing all protocol stack functions.
18
Q
What is a Reduced Function Device (RFD) in an IoT network?
A
An RFD is an IoT sensor with limited network capabilities that implements a subset of protocol functions and communicates with a central gateway but cannot coordinate or communicate directly with other RFDs.
19
Q
What role does the gateway play in an IoT network with RFDs?
A
The gateway oversees the network coordination and handles the full protocol stack functions such as security, overflow control, and congestion control.
20
Q
What is a point-to-point communication structure in IoT?
A
In a point-to-point structure, a single sensor exchanges data with one gateway via a dedicated link, allowing an individual session between them.
21
Q
What is an example of a point-to-point communication structure?
A
A TV remote control is an example of point-to-point communication.
22
Q
What is an example of a point-to-point communication structure?
A
A TV remote control is an example of point-to-point communication.
23
Q
What is a point-to-multipoint connectivity structure in IoT?
A
In a point-to-multipoint structure, a single gateway communicates with multiple IoT nodes simultaneously, sharing the transmission medium and channel.
24
Q
What is the difference between spatially-shared and time-shared communication channels in IoT?
A
In spatially-shared connections (frequency division), multiple IoT nodes use the channel at the same time. In time-shared connections (time division), IoT nodes take turns to communicate with the gateway.
25
What is the physical topology of a network?
The physical topology refers to the geometric layout of how devices are connected via links in a network.
26
Which are the two most common network topologies in IoT networks?
Mesh and star topologies are the two most common topologies in IoT networks.
27
What does the network topology represent in an IoT network?
The network topology represents the geometric relationship between the links and nodes, or the organization of the nodes in the network.
28
What type of communication occurs in a mesh network topology?
In a mesh network topology, there is a point-to-multipoint communication link, where data can hop from one node to another before reaching the gateway
29
What roles can sensor nodes serve in a mesh network?
Sensor nodes in a mesh network can serve as endpoints, transmitting their own data, or as repeaters, relaying data from other nodes or sensors.
30
What is a full mesh network topology?
In a full mesh network topology, all homogeneous nodes are fully interconnected and can serve as repeaters, implementing the full protocol functions and coordinating communication.
31
What is the difference between full mesh and partial mesh networks?
In a full mesh network, all nodes are interconnected and can act as repeaters, whereas in a partial mesh network, only selected nodes serve as repeaters, and Reduced Function Devices (RFDs) can only transmit data to relaying nodes.
32
Why is full mesh topology uncommon in IoT networks?
Full mesh topology is uncommon because endpoint sensors usually transmit data directly to a gateway rather than distributing it among other nodes, and the coverage is limited since all nodes need to be within range of each other.
33
How do short-range IoT technologies like ZigBee and Z-Wave benefit from mesh topology?
ZigBee and Z-Wave benefit from mesh topology by extending their coverage through multiple repeaters and relaying nodes, allowing them to cover larger areas like commercial buildings or industrial fields.
34
What is a drawback of using mesh topology to extend coverage?
Extending coverage in mesh topology often results in lower data rates due to the time required for intermediate nodes to relay messages.
35
What are some challenges of scaling large mesh networks?
Challenges include high installation costs due to many relaying nodes, increased power consumption as relaying nodes must stay awake, and vulnerability to security attacks if a relaying node is compromised.
36
What is a self-healing capability in mesh networks, and why is it important?
Self-healing allows data to be rerouted through alternative links if a relaying node fails, enhancing the robustness and reliability of the network.
37
For what types of IoT use cases is mesh topology most suitable?
Mesh topology is suitable for IoT use cases in consumer marketplaces, such as smart homes, where coverage and the number of sensors are limited.
38
What type of communication structure is used in a star network topology?
In a star network topology, each sensor node has a point-to-point communication link with a central hub or gateway, which handles all protocol functions.
39
Why is star topology simpler and cheaper to deploy than mesh topology?
Star topology is simpler because all communication is directed through a central hub or gateway, and it requires fewer relaying nodes than mesh topology.
40
How does star topology generally offer higher security compared to mesh topology?
Star topology offers higher security because the sensor nodes are not directly connected to each other, and all communication is coordinated by a sophisticated gateway equipped with security mechanisms.
41
What is a disadvantage of star topology?
A disadvantage of star topology is its dependence on a single hub; if the hub fails, the entire network collapses.
42
How is the coverage of star networks limited, and how can it be extended?
The coverage of star networks is limited to the transmission range of the gateway and sensor nodes. However, LPWA IoT access technologies can extend the coverage to tens of kilometers in rural or line-of-sight areas.
43
What is the advantage of LPWA star networks in terms of energy efficiency?
LPWA star networks allow endpoint devices to go into deep sleep mode, conserving energy and enabling small IoT sensors to run for years on a coin battery.
44
What types of IoT use cases are star topologies most suitable for?
Star topologies are suitable for massive IoT use cases, such as oil and gas, mining, and forestry, where thousands of devices are distributed over large geographic areas.
45
Why is scaling and managing star networks easier than mesh networks?
Scaling and managing star networks is easier because they have fewer relaying nodes and centralized communication through a hub, making configuration more straightforward.
46
What is the purpose of IoT network protocols?
IoT network protocols define the rules to ensure that messages transmitted between IoT devices are understood and that the data exchanged is secure.
47
Why are different application-layer IoT protocols used for different IoT use cases?
Different IoT use cases have varying requirements, such as speed, reliability, power consumption, and bandwidth. Specific protocols are optimized to meet these needs.
48
What are some common IoT protocols?
The common IoT protocols include MQTT, CoAP, AMQP, and sometimes HTTP, though HTTP is not ideal for constrained devices due to its high power consumption and complexity.
49
Why is HTTP not ideal for IoT applications?
HTTP is a heavy and power-hungry protocol that is better suited for browser-based clients on devices with higher capabilities like smartphones.
50
What is MQTT, and why is it widely used in IoT?
MQTT (Message Queue Telemetry Transport) is a lightweight, low-power, and scalable publish/subscribe protocol ideal for constrained networks with limited bandwidth and power, such as temperature sensors and water flow meters.
51
How does MQTT differ from HTTP in terms of communication?
In MQTT, the broker pushes data to subscribers, whereas in HTTP, clients must pull data from the server. Additionally, MQTT is faster and consumes less power than HTTP.
52
What is the role of the broker in MQTT?
The broker in MQTT acts as a central server that relays messages between publishers and subscribers, handling the entire communication process without the need for direct communication between IoT devices.
53
What does it mean that MQTT is "device agnostic"?
MQTT is device agnostic, meaning IoT devices from various manufacturers with different communication standards can communicate through the broker without needing to be compatible with each other.
54
Explain the role of a "topic" in MQTT.
A topic in MQTT is like an address that organizes messages. Devices subscribe to specific topics (e.g., "home/room/sensors/temperature") to receive messages relevant to them.
55
How does MQTT support many-to-many communication?
MQTT supports many-to-many communication by allowing multiple devices to publish and subscribe to different topics through the broker. This enables devices to send sensor data and receive control commands simultaneously.
56
What are the three QoS levels in MQTT, and how do they differ?
QoS Level 0: Messages are delivered with no guarantee of delivery or acknowledgment (fire-and-forget).
QoS Level 1: Messages are delivered at least once, but duplicates are possible.
QoS Level 2: Messages are delivered exactly once, with no duplication.
57
What network layer model does MQTT use, and why is it considered reliable?
MQTT uses the Transmission Control Protocol/Internet Protocol (TCP/IP) model, which provides reliable, lossless, and connection-oriented communication, ensuring messages are transferred without loss.
58
What is the process of establishing communication in MQTT?
MQTT communication involves a three-phase handshake process between the publisher and the broker to establish a TCP connection. Data is transferred only after the connection is established, and the connection is terminated once the transfer is complete.
59
For what type of IoT devices and use cases is MQTT most suitable?
MQTT is ideal for IoT devices with low power and limited bandwidth, such as temperature sensors, water flow meters, and devices in remote areas where constrained network connections are needed.
60
Why is MQTT scalable in IoT networks?
MQTT is scalable because it supports multiple publishers and subscribers, and new devices can be easily added without needing to change the existing infrastructure.
61
Why is securing the MQTT connection the broker's responsibility rather than the devices’?
Many IoT devices are simple and inexpensive, lacking the necessary network capabilities for secure connections. In MQTT, the broker handles security, allowing IoT devices to communicate only through it and requiring authentication.
62
How does the MQTT broker provide security for IoT devices?
The MQTT broker uses Transport Layer Security (TLS) encryption, and connections are protected by username and password. Additionally, devices are decoupled from each other, so they do not know each other’s IP addresses.
63
What are the different ways an MQTT client can be identified?
Client IDs: Used when subscribing to a topic.
Usernames and passwords: Required for establishing a connection but transmitted in plain text.
Client certificates: A secure but complex method, typically used for high-security clients.
64
What is the security risk associated with MQTT's username and password authentication?
Since the username and password are transmitted in plain text without encryption, they can be intercepted unless additional security measures like TLS are used.
65
What happens if the MQTT broker fails, and how can this be prevented?
If the broker fails, the entire network collapses, as the broker is the central communication point. To prevent this, brokers support redundancy, where a secondary broker takes over in case the primary one fails.
66
How does MQTT reduce network load?
The MQTT publishers only send data when it differs from the previously sent information. This reduces unnecessary transmissions.
67
What is the function of the following certificates in MQTT: birth, death, and last will and testament?
Birth certificate: Issued when a new publisher connects to the broker.
Death certificate: Issued when a client disconnects and stops sending data.
Last will and testament: Sent by the broker to subscribers when a client suddenly disconnects.
68
What is the security risk associated with MQTT's username and password authentication?
Since the username and password are transmitted in plain text without encryption, they can be intercepted unless additional security measures like TLS are used.
69
What happens if the MQTT broker fails, and how can this be prevented?
If the broker fails, the entire network collapses, as the broker is the central communication point. To prevent this, brokers support redundancy, where a secondary broker takes over in case the primary one fails.
70
How does MQTT reduce network load?
The MQTT publishers only send data when it differs from the previously sent information. This reduces unnecessary transmissions.
71
What is the function of the following certificates in MQTT: birth, death, and last will and testament?
Birth certificate: Issued when a new publisher connects to the broker.
Death certificate: Issued when a client disconnects and stops sending data.
Last will and testament: Sent by the broker to subscribers when a client suddenly disconnects.
72
What is CoAP, and what type of networks is it designed for?
CoAP (Constrained Application Protocol) is a lightweight application layer protocol, optimized for devices with limited capabilities and suitable for machine-to-machine (M2M) communications.
73
How does CoAP differ from MQTT in terms of the transport layer it uses?
CoAP uses the User Datagram Protocol (UDP), while MQTT relies on Transmission Control Protocol (TCP).
74
What role does the Uniform Resource Identifier (URI) play in CoAP?
The URI is used to uniquely identify resources. For example, a temperature sensor using CoAP might have a URI like coap://devices/sensors/temperature to identify its messages.
75
How does the CoAP request/response model work?
A CoAP client sends a UDP packet to request data from a server. The server responds with a packet containing the requested data. The client may also push data to the server by posting to its URI.
76
What is the key difference in the transport layer between MQTT and CoAP?
MQTT uses TCP for reliable, connection-oriented communication, whereas CoAP uses UDP for lightweight, connectionless communication.
77
Which protocol (MQTT or CoAP) would be more suitable for constrained IoT devices, and why?
CoAP is more suitable for constrained devices due to its lightweight nature and reliance on UDP, which consumes fewer resources compared to MQTT’s use of TCP.
78
What are the two message types used by CoAP for reliability?
CoAP uses Confirmable (CON) and Non-
confirmable (NON) messages.
79
What is a Confirmable (CON) message in CoAP?
A Confirmable (CON) message is a reliable message in CoAP where the client keeps sending the message until it receives an Acknowledgement (ACK) from the server with the same ID.
80
Which MQTT QoS level is similar to CoAP’s Confirmable message?
CoAP’s Confirmable message is similar to QoS level 1 in MQTT.
81
What is a Non-confirmable (NON) message in CoAP?
A Non-confirmable (NON) message is an unreliable message in CoAP, where no acknowledgement is expected from the server.
82
Which MQTT QoS level corresponds to CoAP’s Non-confirmable message?
CoAP’s Non-confirmable message corresponds to QoS level 0 in MQTT.
83
What type of protocol is CoAP by default in terms of security?
CoAP is a plaintext protocol by default, similar to HTTP.
84
How is CoAP’s connection secured?
CoAP uses Datagram Transport Layer Security (DTLS), which runs over UDP, to secure its connection and encrypt data.
85
What is the purpose of DTLS in CoAP?
DTLS ensures encrypted and secure communication in CoAP, providing protection over the inherently unsecured UDP.
86
What is Advanced Message Queuing Protocol (AMQP)?
AMQP is a lightweight application layer protocol that supports both publish/subscribe and request/responsemessaging models.
87
What type of protocol is AMQP in terms of connection?
AMQP is a connection-oriented protocol that uses TCP services.
88
What are the main advantages of using AMQP?
AMQP is optimized for higher reliability and security and features simple provisioning and interoperability.
89
How many quality-of-service levels does AMQP support for delivering IoT messages?
AMQP supports two quality-of-service levels.
90
What is the unsettle format in AMQP?
The unsettle format in AMQP is a messaging type similar to MQTT QoS level zero, where message delivery is not acknowledged.
91
What is the settle format in AMQP?
The settle format in AMQP is a reliable messaging model similar to MQTT QoS level one, where message delivery is acknowledged.
92
In what messaging models does AMQP operate?
AMQP operates in both publish/subscribe and request/response messaging models.
93
What factors determine the choice of IoT communication technologies?
The choice of IoT communication technologies is determined by the requirements of specific IoT use cases, including data rates, range, and throughput.
94
How do different IoT use cases affect data transmission requirements?
Some use cases require high data rates for short-range transmission (e.g., smart homes), while others can tolerate lower throughput with longer-range communication (e.g., mining and forestry).
95
What is the role of the Things layer in the IoT core functional stack?
The Things layer includes smart devices responsible for measuring and collecting physical data, such as sensors, actuators, microprocessors, communication modules, and power sources.
96
What is the function of the Connectivity or Communications layer in the IoT stack?
The Connectivity layer connects smart devices to the network via IoT access technologies (e.g., Wi-Fi, cellular), enabling the transportation of data from sensors to the internet.
97
What key questions should be asked to determine suitable technologies for an IoT application?
The following questions should be considered:
* Report range: How far is the IoT sensor from the gateway?
* Report frequency: How often do the IoT sensors send messages?
* Throughput: What is the required data transmission speed?
* Message size: What is the size and complexity of the messages?
* Power consumption: Is the device battery-powered, and what is its required battery life?
* Latency: Is low latency critical for the use case?
* Mobility: Are the sensors mobile or static?
* Cost: What is the budget for communication hardware and fees?
98
Why is understanding the message size important when selecting IoT communication technologies?
Understanding the message size helps determine the capacity needs of the communication technology and whether it can handle rich data or simple messages effectively.
99
How does power consumption impact the choice of IoT devices?
If an IoT device is battery-powered, the power consumption needs to be low enough to ensure a long battery life, affecting the selection of communication technologies.
100
What does latency refer to in IoT applications, and why is it important?
Latency refers to the delay in transmitting messages from the sensor to the gateway. It is crucial for mission-critical applications where timely data delivery is essential.
101
How does mobility influence the selection of IoT technologies?
If IoT sensors are mobile, the communication technology must support dynamic connections, potentially impacting the choice of protocols and network design.
102
What is the ultimate goal of answering the key questions about IoT use cases?
The goal is to enable the IoT network architect to compare available access technologies and select the most suitable one to meet the specific requirements of the IoT application.
103
What are the advantages of wired IoT communications like Ethernet and PLC?
Wired IoT communications such as Ethernet and PLC are secure, reliable, and support high data rates, making them suitable for stationary devices located near each other.
104
What are the main limitations of wired IoT technologies?
The main limitations include high implementation costs (due to cabling), low scalability, and limited range (typically tens of meters).
105
What is Ethernet, and what are its key characteristics?
Ethernet is a widely used Local Area Network (LAN) technology that connects IoT devices via cables. It supports high data rates (up to tens of Gbps) and ultra-low latency, making it ideal for mission-critical applications.
106
How does Power-Line Communication (PLC) work, and what are its advantages?
PLC connects IoT devices through existing power lines using sophisticated modulation techniques. It reduces cabling costs and can provide longer ranges (up to a few kilometers) and reasonable data rates (hundreds of Kbps).
107
What types of PLC technologies exist and how do they differ?
Two main types of PLC technologies are:
- Narrow-Band PLC (NB-PLC): Operates in the frequency range of 300—500 kHz, supporting data rates of hundreds of Kbps.
- Broadband PLC: Operates at higher frequencies (1.8 MHz to 250 MHz) and supports higher data rates (up to several hundred Mbps) over shorter ranges.
108
In what scenarios is PLC considered a suitable IoT technology?
PLC is suitable for dense urban areas where signal attenuation of wireless networks is significant, particularly for connecting environmental sensors to the internet.
109
What are the advantages of wireless IoT communication technologies?
Wireless IoT technologies are typically more cost-effective, scalable, and allow easy addition of new devices to the network, making them ideal for mobile and smart devices.
110
What are the two categories of wireless access technologies?
The two categories are short-range technologies and low-power wide-area (LPWA) technologies.
111
Which wireless technologies are commonly used for short-range communication?
Common short-range technologies include NFC, Bluetooth, ZigBee, Z-Wave, Thread, WirelessHART, and Wi-Fi. Bluetooth, ZigBee, and Wi-Fi are especially prevalent in applications like smart homes and healthcare.
112
What is Bluetooth Low Energy (BLE), and what are its specifications?
BLE is a power-optimized version of Bluetooth suitable for battery-operated IoT devices. It can achieve data rates of up to 2 Mbps and a range of up to 100 meters.
113
What are the key features of ZigBee technology?
ZigBee operates based on the IEEE 802.15.4 standard, supports mesh networks, delivers data rates of up to 250 kbps, and has a range of up to 100 meters. It can connect up to 64,000 IoT devices.
114
How does ZigBee provide reliability in networks?
ZigBee networks are self-healing and self-forming, allowing them to dynamically reconfigure and automatically set up connections among devices.
115
What are the main characteristics of Wi-Fi technology in IoT?
Wi-Fi is widely used for IoT applications requiring low latency and high data rates. The latest version, Wi-Fi 6, supports data rates up to 9.6 Gbps.
116
What is Industrial Wi-Fi (Wi-Fi HaLow), and what makes it suitable for IIoT?
Wi-Fi HaLow operates in sub-gigahertz frequencies, providing enhanced coverage, making it suitable for Industrial Internet of Things (IIoT) applications requiring high data rates and large coverage areas.
117
What are LPWA technologies, and what advantages do they offer?
LPWA technologies allow long-range communication with extremely low power consumption, enabling battery-operated sensors to operate for years with minimal data transmission.
118
What are the two categories of LPWA technologies based on their frequency spectrum?
The categories are unlicensed spectrum LPWA (e.g., LoRaWAN, Sigfox) and licensed spectrum LPWA(e.g., NB-IoT, LTE-M).
119
What are the maximum data rates for LoRaWAN and Sigfox technologies?
LoRaWAN supports a maximum data rate of 27 kbps, while Sigfox supports up to 100 bps.
120
What advantages do licensed LPWA technologies like NB-IoT and LTE-M have over unlicensed ones?
Licensed LPWA technologies offer ubiquitous cellular coverage, reliability, security, and better scalability, making them suitable for massive IoT use cases.
121
What are the key differences between LTE-M and NB-IoT?
LTE-M supports data rates up to 1 Mbps and a bandwidth of 1.4 MHz, while NB-IoT has lower maximum data rates (tens of kbps) and a reduced bandwidth of 200 KHz.
122
In what use cases is NB-IoT considered suitable?
NB-IoT is suitable for delay-tolerant IoT applications with light messaging requirements, such as smart meters, due to its higher latency and reduced complexity.
123
What factors influence the choice of network topology, protocols, and technologies for IoT applications?
Factors include report range, report frequency, message type and size, power availability, mobility, and other characteristics of IoT smart objects.
124
What are the two most common network topologies used in IoT applications?
The two most common topologies are mesh topology and star topology.
125
What are the advantages of mesh network topology in IoT?
Mesh networks are more reliable and provide better redundancy but can be more difficult to implement.
126
What are the benefits of star network topology in IoT applications?
Star topology is easier to implement and allows for easy scalability, though the network size is limited by the transmission range of the IoT sensors and the gateway.
127
Which protocols are commonly used in the application layer for IoT messaging?
Commonly used protocols include MQTT, CoAP, AMQP, and sometimes HTTP.
128
Why is HTTP not considered optimized for IoT applications?
HTTP is not optimized for IoT applications because it is heavier and not designed for the lightweight communication needs typical in IoT environments.
129
What role do IoT access technologies play in IoT communications?
IoT access technologies facilitate effective communication between IoT sensors and software backends.
130
What are some examples of short-range access technologies used in IoT?
Examples of short-range technologies include ZigBee, Bluetooth, and Wi-Fi.
131
In what types of scenarios are short-range technologies like ZigBee, Bluetooth, and Wi-Fi commonly used?
These technologies are common in smart homes.
132
In what types of scenarios are short-range technologies like ZigBee, Bluetooth, and Wi-Fi commonly used?
These technologies are common in smart home applications where IoT devices are located near each other.
133
What is the purpose of Low-Power Wide-Area (LPWA) technologies in IoT?
LPWA technologies support IoT applications in larger geographic areas, allowing many devices to transmit small amounts of data over long distances.
134
What are the two categories of LPWA technologies?
The two categories are licensed spectrum LPWA (e.g., LTE-M and NB-IoT) and unlicensed spectrum LPWA(e.g., LoRaWAN and Sigfox).
135
What types of connectivity needs do LPWA technologies address?
LPWA technologies address the connectivity needs of massive IoT applications where numerous devices in wide areas need to transmit small amounts of data.
136
How do licensed LPWA technologies differ from unlicensed ones?
Licensed LPWA technologies, like LTE-M and NB-IoT, require subscription fees for frequency usage, while unlicensed technologies, like LoRaWAN and Sigfox, operate in unlicensed frequency bands and are typically easier to deploy.
137
What is a key feature of ZigBee technology that makes it suitable for IoT?
ZigBee supports mesh networking, which allows for better communication and reliability among devices.
138
What are some challenges associated with implementing mesh networks in IoT?
Mesh networks can be more complex to implement due to the need for multiple nodes to communicate with one another.
139
What type of IoT application would benefit most from star topology?
Applications where devices are geographically close and require simple connections, such as in a small smart home network, would benefit from star topology.
140
What are the characteristics of LPWA technologies that make them suitable for IoT?
LPWA technologies are characterized by low power consumption, long-range communication capabilities, and the ability to support a large number of devices.
141
Why are MQTT, CoAP, and AMQP preferred for lightweight IoT applications?
These protocols are designed for low overhead, making them suitable for devices with limited processing power and memory, which is common in IoT environments.
142
What type of data rates do LPWA technologies typically support?
LPWA technologies typically support low data rates sufficient for small amounts of data to be transmitted intermittently.
143
How do the range and data rate capabilities of short-range technologies compare to LPWA technologies?
Short-range technologies typically support higher data rates but over shorter distances, while LPWA technologies enable longer-range communication with lower data rates.
* home applications where IoT devices are located near each other.
144
What is the purpose of Low-Power Wide-Area (LPWA) technologies in IoT?
LPWA technologies support IoT applications in larger geographic areas, allowing many devices to transmit small amounts of data over long distances.
145
What are the two categories of LPWA technologies?
The two categories are licensed spectrum LPWA (e.g., LTE-M and NB-IoT) and unlicensed spectrum LPWA(e.g., LoRaWAN and Sigfox).
146
What types of connectivity needs do LPWA technologies address?
LPWA technologies address the connectivity needs of massive IoT applications where numerous devices in wide areas need to transmit small amounts of data.
147
How do licensed LPWA technologies differ from unlicensed ones?
Licensed LPWA technologies, like LTE-M and NB-IoT, require subscription fees for frequency usage, while unlicensed technologies, like LoRaWAN and Sigfox, operate in unlicensed frequency bands and are typically easier to deploy.
148
What is a key feature of ZigBee technology that makes it suitable for IoT?
ZigBee supports mesh networking, which allows for better communication and reliability among devices.
149
What are some challenges associated with implementing mesh networks in IoT?
Mesh networks can be more complex to implement due to the need for multiple nodes to communicate with one another.
150
What type of IoT application would benefit most from star topology?
Applications where devices are geographically close and require simple connections, such as in a small smart home network, would benefit from star topology.
151
What are the characteristics of LPWA technologies that make them suitable for IoT?
LPWA technologies are characterized by low power consumption, long-range communication capabilities, and the ability to support a large number of devices.
152
Why are MQTT, CoAP, and AMQP preferred for lightweight IoT applications?
These protocols are designed for low overhead, making them suitable for devices with limited processing power and memory, which is common in IoT environments.
153
What type of data rates do LPWA technologies typically support?
LPWA technologies typically support low data rates sufficient for small amounts of data to be transmitted intermittently.
154
How do the range and data rate capabilities of short-range technologies compare to LPWA technologies?
Short-range technologies typically support higher data rates but over shorter distances, while LPWA technologies enable longer-range communication with lower data rates.
